Incidence of and risk factors for secondary ocular hypertension in moderate to severe infectious ulcerative keratitis

Purpose: The aim of this study was to investigate the incidence of and risk factors for secondary ocular hypertension (OHT) in patients with moderate to severe infectious ulcerative keratitis and to evaluate the long-term outcome of patients with secondary OHT. Patients and methods: A retrospective chart review of 346 patients with moderate to severe infectious keratitis admitted to Siriraj Hospital during the period from 1 January 2005 to 31 May 2008 was conducted. Secondary OHT was defined as intraocular pressure (IOP) greater than 21 mmHg or a consistent demonstration of higher IOP in the affected eye of 8 mmHg or greater, at any time before resolution of the ulcer. The incidence of and the risk factors for secondary OHT were determined. Among the patients with secondary OHT, the incidence of and the risk factors for persistent elevated IOP and blindness at the last follow-up were also evaluated. Results: Two hundred and two eyes were included in the study. The incidence of secondary OHT was 45.5%. Severe keratitis and severe anterior chamber cells' reaction were the risk factors for IOP elevation during active keratitis (P=0.003 and 0.018, respectively). Long-term data were available for 69 patients with OHT; 32.9% (22/69) developed persistent IOP elevation after keratitis resolved. Older age (P=0.007) and hyperosmotic agents used during active keratitis (P=0.028) were associated with persistent IOP elevation. Age was also associated with blindness among the patients with secondary OHT (P=0.002). Conclusion: Moderate to severe infectious keratitis was associated with a high incidence of secondary OHT. Two main risk factors were severe corneal infiltration and severe intraocular inflammation. One-third of the patients with OHT developed persistent elevated IOP after keratitis was healed. Older age and hyperosmotic agents used during active keratitis were significantly associated with persistent elevated IOP. Older age was also associated with poorer visual outcome.